[Pathological examination of radial artery--as a graft material for coronary artery bypass grafting].

To evaluate the usefulness of the radial artery (RA) as a graft material for coronary artery bypass grafting (CABG), the histologic studies of the RA were performed. Specimens were obtained from both sides of 10 RAs during the operations. The degree of arteriosclerosis was evaluated by two methods. The one was microscopic examination by a pathologist, while the other was used by NIH Image 1.57 system. Using this system, the pathological index of arteriosclerotic change was expressed as a ratio (Rx: internal luminal area/tunica media area) of the cross section. From the pathological view the tunica media of RA was rich in smooth muscle cells and poor in elastic fiber. And there was little arteriosclerosis in this artery. The mean Rx of the proximal side of RA was 0.177 +/- 0.033 and that of the distal side was 0.258 +/- 0.132. There was no significant difference between the two, but the proximal side of the RA was slightly larger than the distal. These results showed that RA has a low grade of arteriosclerosis. This was confirmed on microscopic examination. According to these results, the RA can be expected to be a suitable bypass material for CABG.